Experiments were done with a new oral killed B subunit - whole cell cholera vaccine, BS-WC, and its antitoxic protective activity was compared with live CVD 103 HgR vaccine. Intraperitoneal immunization of mice and subsequent challenge with purified cholera toxin (CT) were employed to evaluate the anti-cholera protective effect of the new vaccines. CVD 103-HgR vaccine demonstrated 100% protection of mice against 2.25 LD50 and 70% against 3 LD50 of CT. Mice immunized with BS- WC vaccine were protected against 2.25 and 3 LD50 of CT in 88% and 62%, respectively. All three killed parenteral vaccines failed to protect against CT.